1. Field of the Invention
The present invention relates to hydraulic fracturing additives, to hydraulic fracturing treatment fluids made therefrom, to methods of hydraulically fracturing a well. In another aspect, the present invention relates to hydraulic fracturing additives comprising polymer and fibers or comminuted plant materials, to hydraulic fracturing treatment fluids made therefrom, to methods of hydraulically fracturing a well using such fluids.
2. Description of the Related Art
The productivity or injectivity of a wellbore in fluid communication with a subterranean hydrocarbon-bearing formation may be undesirably low due to a number of causes, including low permeability of the formation rock, placement of casing cement, plugging by previously injected materials, clay damage, or produced fluid damage. Productivity or injectivity may be increased by hydraulically fracturing the formation.
Hydraulic fracturing generally entails injecting a fluid into the wellbore at a sufficient rate and pressure to overcome the tensile strength of the formation and the overburden pressure. The injected fluid creates cracks or fractures extending from the wellbore out into the formation which are usually propped open with a solid proppant entrained in the fluid. The fractures permit the flow of hydrocarbons and other fluids into or out of the wellbore.
U.S. Pat. No. 3,816,151 to Podlas, U.S. Pat. No. 3,938,594 to Rhudy et al and U.S. Pat. No. 4,137,182 to Golinkin disclose hydraulic fracturing processes using a number of crosslinked polymer solutions as fracturing fluids.
U.S. Pat. No. 4,779,680, issued Oct. 25, 1988 to Sydansk, notes that many of the then prior art crosslinking reactions prescribed were very difficult to control. Sydansk further notes that uncontrolled crosslinking can occur too rapidly, producing a non-homogeneous suspension of highly viscous gel balls in a watery solution, or in the other extreme crosslinking can fail to occur at all. In either case, the result is an ineffective fracturing fluid.
Sydansk even further notes that at that time, a process is needed for hydraulically fracturing a subterranean hydrocarbon-bearing formation with a stable homogeneous viscous fracturing fluid having satisfactory performance properties to meet the demands of the fracture treatment.
As a solution to the deficiencies and needs of the prior art, Sydansk, discloses the use of a water soluble carboxylate crosslinking polymer along with a chromic carboxylate complex crosslinking agent as a lost circulation material.
While U.S. Pat. No. 5,377,760, issued Jan. 3, 1995 to Merrill discloses addition of fibers to an aqueous solution of partially hydrolyzed polyacrylamide polymer, with subsequent injection into the subterranean to improve conformance, the requirements of a hydraulic fracturing fluid are so different from a conformance fluid, that such would not necessarily work for hydraulic fracturing treatment.
Additionally, Merrill's conformance treatment method of mixing the fibers with the polymer solution followed by injection, requires a multiplicity of storage and mixing tanks, and a metering system which must be operated during the operation of the well. Specifically, a first tank will store a water and polymer solution, a second tank will store a water and cross-linking solution, and a third tank will be used to mix fibers with polymer solution from the first tank to create a polymer/fiber slurry. This polymer/fiber slurry is then metered from the third tank and combined with crosslinking solution metered from the second tank to the well bore.
Thus, in spite of the advancements in the prior art, there still need for further innovation in the hydraulic fracturing additives.
There is need for further innovation for hydraulic fracturing additives utilizing a water soluble polymer.
There is another need for a hydraulic fracturing additive which would allow for simplification of the mixing equipment.
These and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its drawings and claims.